An investigation of the conformational dynamics of protein-lipid interactions in model liposomes and in the sarcoplasmic reticulum of rabbit skeletal muscle by laser Raman spectroscopy is proposed. The study is based on interpretations of conformationally sensitive. Raman active vibrations for these mixed systems which have recently been developed by the principal investigator and others for determinations of protein secondary structure and phospholipid hydrocarbon side chain conformation. The project will focus on changes in both the backbone structure of proteins and in the hydrocarbon side chains of phospholipids associated with 1) polar surface binding; 2) mixed polar-hydrophobic interactions; and 3) hydrophobic internal binding by examining changes in Raman active protein amide vibrations and phospholipid C-C and CH2 vibrations accompanying lipid-protein binding in model liposome systems. To complement this model membranes approach, a Raman spectroscopic investigation of the sarcoplasmic reticulum (SR) of rabbit skeletal muscle is proposed to pinpoint conformational changes accompanying additions of divalent cations, ATP or removal of extrinsic in intrinsic proteins.